主权项 |
1. An integrated circuit comprising:
A. input pads; B. output pads; C. first core circuitry having an input coupled to an input pad and having an output; D. second core circuitry having an input coupled to the output of the first core circuitry and having an output coupled to an output pad; E. test connection circuitry having an input coupled with the input pad and having an output coupled with the input of the second core circuitry; and D. output circuitry including:
i. a tri-state buffer having a core input, a data output coupled to an output pad, and a tristate enable input;ii. comparator circuitry having a core input coupled to the core input of the tri-state buffer, a response input coupled to the output pad, and an enable input lead coupled to the tristate enable input of the tri-state buffer; andiii. multiplex circuitry having a first input coupled to the output of the first core circuitry, a second input coupled to the output of the second core circuitry, a core select input, and a selected core output coupled to the core input of the tri-state buffer circuitry. |